Building automation systems are supposed to save energy. Vendors promise 10-25% reductions. Industry studies support these claims. Yet many building owners see their BMS as a maintenance burden rather than an energy-saving tool.
"If your BMS isn't delivering energy savings, you're not alone — and there are usually fixable reasons."
Common Reasons BMS Systems Underperform
1. "Set It and Forget It" Mentality
Signs this is your problem:
- Schedules don't match actual building use
- Setpoints were set for tenants who left years ago
- Sequences reference equipment that's been replaced
The fix: Regular operational reviews. At minimum, annual review of schedules, setpoints, and sequences.
2. Override Abuse
Overrides are necessary for troubleshooting. But overrides that stay in place become energy waste.
Red Flags
Multiple outputs in manual mode • Equipment running 24/7 that should be scheduled • Valves locked in position
The fix: Regular override audits. Set a policy that all overrides expire automatically or require monthly justification.
3. Sensor Calibration Drift
Your BMS can only be as smart as its sensors. A space temp sensor reading 3°F too high causes the system to overcool all day, every day.
The fix: Annual verification of critical sensors against calibrated references.
4. Broken or Disabled Economizers
- Damper actuators failed and never replaced
- Sequences disabled after troubleshooting
- Temperature sensors drifted, causing incorrect operation
Signs: Mechanical cooling running on mild days • Outdoor air dampers always at minimum • No change in operation when outdoor conditions are ideal
The fix: Verify economizer operation during shoulder seasons. Repair or recalibrate as needed.
5. No Optimization of Original Sequences
Original programming is often conservative — designed to ensure comfort, not optimize efficiency.
- Optimal start/stop based on actual building response
- Supply air temperature reset based on zone demands
- Chilled water temperature reset based on load
- Static pressure optimization in VAV systems
Prioritizing Improvements
- Fix broken economizers
- Correct schedule mismatches
- Clear long-standing overrides
- Calibrate critical sensors
- Implement supply air temp reset
- Optimize equipment staging
- Improve equipment integration
- Add energy monitoring
What Good BMS Energy Management Looks Like
A properly optimized BMS:
- Adjusts operation based on actual conditions and occupancy
- Uses free cooling when available
- Runs equipment only as hard as needed to maintain comfort
- Provides visibility into energy consumption
- Alerts operators to anomalies and waste
- Receives regular attention and adjustment
Getting Your BMS to Deliver
At Controls NYC, we help building owners unlock the energy savings their BMS should provide:
- Operational audits to identify problems
- Optimization programming and commissioning
- Ongoing monitoring and adjustment services
- Training for building staff
Contact us to discuss how to make your BMS actually save energy.
Ready to Discuss Your Building?
Whether you're evaluating an upgrade, dealing with a failing system, or just want a second opinion — we're happy to talk through your options.
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